Generally, in the case of the same carbon equivalent, increasing the ratio of silicon to carbon will increase the tendency of ferrite formation. However, for the thin-walled small pieces of Water Pump Castings, the increase of the ratio of silicon to carbon, the tendency of ferrite in the organization Is not large, so it will not affect its strength.

(1) line shrinkage. The higher the formation temperature of the solid liquid skeleton, the earlier the start of the line shrinkage, the longer the contraction time, the greater the line shrinkage value. At the same carbon equivalent, the increase in the ratio of silicon to carbon increases the number of primary austenite and forms a solid skeleton earlier, resulting in an increase in line shrinkage. However, in the actual production, high carbon carbon than the cast iron carbon equivalent compared with the previous process is not very different, the impact of line contraction is also small, in practice did not find the reasons for the resulting waste.

(2) body contraction. The traditional process of cast iron and high silicon than iron compared to cast iron, carbon content is low, but the carbon equivalent is slightly higher, so this cast iron body shrinkage no significant difference. This feature has also been validated in production.

(3) section sensitivity. High silicon is less sensitive than cast iron, which is important for submersible pumps that are often subjected to impact.

With regard to the requirement of the ingot process of the Water Pump Castings, the composite treatment method of the original hot metal component is adopted. Or 0 degrees dilute magnesium alloy and 1 degree of rare earth ferrosilicon alloy mix after half into the bottom of the ladle. Above the iron plate or perlite powder covered, and then the remaining half into the trough with molten iron into the ladle into the creep reaction, to be completed after the reaction, adding inoculants for treatment to clean the molten iron worm-like Graphite cast iron. The creep treatment temperature is generally not less than 1400 degrees Celsius.